In this type of questions, some clues regarding seating or placing sequence (linear or circular) of some persons or items is given. The candidate is required to form the proper sequence using these clues and answer the questions accordingly.

Seven books are placed one above the other in a particualr way.

History book is placed exactly above Civics book.

Geography book is fourth from the bottom and English book is fifth from the top.

There are two books in between Civics and Economics books.

How many books are there between Civics and Science books ?To answer this question, which other extra information is required, if any, from the following ?

Option:

A. There are two books between Geography and Science books.

B. There are two books between Mathematics and Geography books.

C. There is one book between English and Science books.

D. The Civics book is before two books above Economics book.

E. No other information is required.

Answer: C . There is one book between English and Science books.

Justification:

Clearly, the sequence of the five books mentioned, from top to bottom is :---, History, Civics, Geography, English, Economics, ----

Clearly, (c) gives us the clue that Science book is placed at the bottom.Thus, we know that there are three books between Civics and Science.